Japan's main opposition party has submitted a bill to parliament to approve same-sex marriage, hoping to pile pressure on the government before the country hosts the G7 summit in May.
The bill, which would revise the Civil Code of laws, is effectively a symbolic measure because the ruling coalition wields a significant majority and has struggled even to agree on measures outlawing discrimination against sexual minorities.
Japan is the only Group of Seven nation that does not recognise same-sex marriage and Prime Minister Fumio Kishida has come under increasing scrutiny over LGBTQ protections in recent weeks.
He drew criticism last week for saying that not recognising same-sex unions "isn't unfair discrimination by the state".
Japan's 1947 constitution stipulates that "marriage shall be only with the mutual consent of both sexes", although recent polls show a majority of Japanese favour recognising same-sex marriage.
"I think it's discrimination if marriage is recognised legally for heterosexual couples but not same-sex couples," said Chinami Nishimura, acting chief of the Constitutional Democratic Party that submitted the bill.
The party also submitted a similar bill with other opposition parties in 2019 but it was not discussed in parliament.
Kishida also came under fire last month after one of his secretaries reportedly made discriminatory comments, including that he "doesn't even want to look at" married same-sex couples.
The aide was promptly fired and Kishida called the remarks "outrageous" and "incompatible" with the inclusive society the government is aiming for.
Japan is not an outlier in Asia, however, where Taiwan is the only place with marriage equality.
Kishida has said same-sex marriage would "change society", so lawmakers must be "extremely careful in considering the matter".
More than a dozen couples have filed lawsuits in district courts across Japan arguing the ban on same-sex marriage violates the constitution.
A Tokyo court said in November Japan's failure to legally protect same-sex partners created an "unconstitutional situation", while also ruling that the constitution's definition of marriage was legal.
Kishida's government is struggling to agree on language outlawing discrimination on the grounds of sexual orientation.
Opponents of the move insist a proposed anti-discrimination clause could deepen social divisions or open up companies and individuals to malicious lawsuits.
